Search results for "plasticizer"
showing 10 items of 63 documents
Evaluation of anti-androgenic activity of di-(2-ethylhexyl)phthalate
2005
International audience; DEHP is a widely used platiciser in the manufacture of PVC-based materials. It is known to disrupt the reproductive tract development in male rats. We have performed the Hershberger assay with DEHP on an immature castrated rat model to check if DEHP antagonise the testosterone propionate androgenic effect on the accessory sex organs development. DEHP significantly decreased the BC/LA muscles, the prostate, and the seminal vesicles relative weights from 100, 200, and 400 mg/kg bw/day, respectively. DEHP increased the liver relative weight from 100 mg/kg bw/day. A study was also performed on MDA-MB453 cell line stably transfected with pMMTVneo-Luc with DEHP and its maj…
Crosslinked chitosan/poly(vinyl alcohol)-based polyelectrolytes for proton exchange membranes
2019
[EN] The preparation polyelectrolytes based on crosslinked poly(vinyl alcohol) (PVA) and chitosan (CS) was considered as a feasible alternative to develop highly functionalised, cost-effective and eco-friendly membranes for proton exchange fuel cell technologies. CS/PVA-based membranes were combined with sulfosuccinic acid (SSA) as crosslinking and sulfonating agent, and glycerol (GL) to promote flexibility and favour their manageability. The chemical structure, the thermo-oxidative behaviour, the ethanol uptake, the electric, the proton conductivity, and the performance in direct ethanol fuel cell (DEFC) were assessed. In general, all the CS/PVA-based polyelectrolytes showed a synergetic i…
Water vapour permeability, thermal and wetting properties of whey protein isolate based edible films
2010
Abstract This study deals with the effect of whey protein isolate (WPI) and glycerol (GLY) used as a plasticizer on some physical properties of cast whey protein isolate (WPI) films. Films were prepared from heated (80 °C for 30 min) aqueous solutions of WPI at 7, 8, 9 and 10% (w/w), GLY (40%, w/w, of WPI) and WPI at 8% (w/w), GLY (30, 40, and 60%, w/w, of WPI). For all types of films, water vapour permeability for four relative humidity differentials (30–100%, 30–84%, 30–75%, and 30–53%), surface and thermal properties were measured. Varying the proportion of WPI and GLY in edible films had some effect on water vapour permeability, wetting and thermal properties of WPI films. A cumulative …
Strength of cellulosic fiber/starch acetate composites with variable fiber and plasticizer content
2014
In this experimental study, the performance of injection-molded short flax and hemp fibers in plasticized starch acetate were analyzed in terms of strength. Parameters involved in the analysis are a variable fiber and plasticizer content. The measured strength of the composites varies in the range of 12–51 MPa for flax fibers and 11–42 MPa for hemp fibers, which is significantly higher than the properties of the unreinforced starch acetate matrix. The micro-structural parameters used in modeling of composite strength were obtained from optical observations and indirect measurements. Some of these parameters were qualitatively verified by X-ray microtomography.
PHB-based films as matrices for pesticides
2002
Abstract The effects of pesticides incorporated into PHB-based polymeric matrices on the biodegradability of films and antifungal efficiency of immobilised pesticides to Botrytis cinerea was studied. The mass loss of tested PHB-based films for 2 weeks was 40–50% and after 4 weeks 92–96% of the initial mass. The fungicides Ronilan and Sumilex immobilised into the polymeric matrices did not depress the film degradation rate. PHB-based films caused changes in the soil microorganism association. Fungicides immobilised in PHB-based matrices decreased the count of the phytopathogenic fungus B. cinerea.
Iron-Catalyzed C(sp2)–C(sp3) Cross-Coupling of Chlorobenzenesulfonamides with Alkyl Grignard Reagents: Entry to Alkylated Aromatics
2018
Alkylated benzosulfonamides are compounds of high importance in organic synthesis, including the production of pharmaceuticals, agrochemicals, and plasticizers. We report the iron-catalyzed C(sp2)–C(sp3) cross-coupling of chlorobenzosulfonamides with alkyl Grignard reagents under mild and sustainable conditions. Electronically and sterically varied benzosulfonamides as well as challenging alkyl organometallics containing β-hydrogen afford alkylated benzosulfonamides in high to excellent yields. Sulfonamide represents the most reactive activating group for iron-catalyzed cross-coupling. The process affords alkylated benzenesulfonamides poised for medicinal chemistry applications and traceles…
Tailoring the anionic function and the side chains of comb-like superplasticizers to improve their adsorption
2015
Nowadays admixtures and especially superplasticizers are unavoidable components of the concrete formulation. The high fluidizing efficiency of the comb-like superplasticizers must not overshadow their high costs. This study aims to determine the PCE structure parameters which influence their adsorption in order to enhance their resistance to sulfate competitive adsorption and thus minimize their dosage. The PCE adsorption has been studied on calcite and ettringite which are both surfaces representative of early hydrating cement. The effect of the POE side chain length and density and also of the PCE anionic function i.e. carboxylate, dicarboxylate or phosphate on the adsorption has been ana…
Tracer diffusion in polymer and organic liquids close to the glass transition studied by forced rayleigh scattering
2007
Translational diffusion coefficients D of photochronic dye molecules have been measured by forced Rayleigh scattering in polymer diluent systems at compositions from pure polymer to pure diluent. D could be measured down to below the glass transition temperature T g. In the pure diluent, D(T g) was found typically about two decades below that in the pure polymer but still far above the Stokes-Einstein prediction extrapolated from high temperatures. Some experimental results are in contrast with predictions from free-volume theory.
Methylcellulose-Based Edible Films and Coatings: 2. Mechanical and Thermal Properties as a Function of Plasticizer Content
1997
Several edible films based on methylcellulose and polyethylene glycol 400 (PEG400) were prepared and stored until equilibration at different relative humidities. Tensile stress−strain curves show very different behaviors as a function of PEG400 and relative humidity. Tensile strength strongly depends on relative humidity and then on water content, more than on PEG400 content. On the contrary, elongation is dependent both on water and PEG400. These differences correspond to the glass transition of the polymer, which affects the elongation more than the tensile strength. However, from DSC measurements, it appears that the PEG400 has no or a very low compatibility with the methylcellulose matr…
Microbiological and ageing performance of polyhydroxyalkanoate-based multilayer structures of interest in food packaging
2014
Polyhydroxyalkanoates undergo crystallization during film processing and storage. In this paper, the physico–chemical ageing properties of multilayer structures based on a commercial polyhydroxybutyrate (PHB) and a polyhydroxybutyrate-co-valerate copolymer with 3% valerate content (PHBV3), containing a nanostructured zein interlayer, were analysed. The microbiological safety of the films was also evaluated by monitoring the growth of an inoculum of Listeria monocytogenes over time. Polyethyleneglycol (PEG) was added to PHBV3 films to facilitate handling as the PHBV3 mutlilayer systems (without plasticizer) cracked during film-formation. Crystallinity, thermal, mechanical, barrier and optica…